1. Field of the Invention
The present invention relates to a coding apparatus and method, a decoding apparatus and method, a data processing system, and a storage medium. In particular, the present invention relates to a coding apparatus and method, a decoding apparatus and method, a data processing system, and a storage medium, which allow information to be embedded into data without deterioration in decoded image and without increase in the amount of data.
2. Description of the Related Art
An example of a technique for embedding information without increasing the amount of data is such that the LSB or the lowest two bits of digital audio data are converted into information to be embedded. In this technique, the fact that the lowest bit or bits of digital audio data do not exert much influence on its sound quality is utilized and the lowest bit or bits of digital audio data are simply replaced by information to be embedded. Therefore, at the time of reproduction, information-embedded digital audio data is output as it is, that is, the digital audio data is output in a state that information is embedded therein because it is difficult to return the information-embedded lowest bit or bits to the original state and the lowest bit or bits do not exert much influence on the sound quality.
However, in the above technique, a signal that is different from the original signal is output. Therefore, influence occurs in the sound quality when the signal is audio data or in the image quality when the signal is video data.